Skateboard



FIG. 1 is an upper perspective view of a skateboard showing the claimed design;

FIG. 2 is a lower perspective view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a side view thereof;

FIG. 6 is a front view thereof; and,

FIG. 7 is a back view thereof.

The broken lines depict environmental structure that forms no part of the claimed design. 

CLAIM The ornamental design for a skateboard, as shown and described. 